ParaTechs Corporation develops innovative technologies for biomedical research while seeking to improve animal welfare for laboratory animals. One of ParaTechs' major goals is to further the guiding principles of ethical animal use by 'reducing, replacing and refining' the use of animals in research, according to the guidelines of Russell and Burch's 3Rs of animal research. ParaTechs already has brought to market a non-surgical embryo transfer device (NSETTM) for mice, which replaces surgical embryo transfers with a non-surgical method that has been proven to cause less stress in research animals. The goal of this project is to develop a device and a research protocol for nonsurgical embryo transfer in rats. The device and protocol is to be rapid, easy to use, cost effective, and efficien for embryo transfer. Poof of principle for the project was established during Phase I, where multiple prototypes of a rat NSET device were designed, manufactured, and tested. Rat embryos were transferred and viable rat pups were obtained, demonstrating the first successful nonsurgical embryo transfer in rats. The goal of Phase II is to further establish the parameters of rat NSET technology and to develop the device for commercialization to the biomedical research community. Four objectives are proposed to achieve this goal. First, we will determine the efficiency of non-surgical embryo transfer relative to surgical embryo transfer in Sprague-Dawley and Fischer 344 rats, for both morula and blastocyst stage embryos. This study will have broad applications for transfer of cryopreserved embryos and for transfer of genetically modified embryos after introduction of embryonic stem cells. Second, we will transfer in vitro cultured embryos using the rNSET and compared efficiency to surgical embryo transfer techniques. This aim will address successful transfer of rat embryos that may be modified very early in development; for example, after pronuclear injection for the purpose of genetic modification. Third, we will test the use of the rat NSET for artificial insemination as an alternative to surgical techniques. This aim will support the use of the device as an alternative t surgical artificial insemination and as a possible alternative to in vitro fertilization. Fourth, w will assess the level of stress reduction of the NSET procedure compared to surgical embryo transfer. These aims are consistent with ParaTechs' overall goal to improve animal welfare and support more effective and humane use of animal models in biomedical research.